Antenna mast construction

ABSTRACT

AN ANTENNA MAST INCLUDING A PLURALITY OF TUBULAR MAST SECTIONS AND A VERTICAL LAUNCH ATTACHMENT ADAPTED TO BE INSTALLED UPON THE LOWERMOST MAST SECTION. THE ATTACHMENT COMPRISES A BRACKET THROUGH WHICH THE REMAINING MAST SECTIONS ARE SEQUENTIALLY INSERTED AND LOCKED TO VER-   TICALLY &#34;LAUNCH&#34; THE MAST TO A DESIRED HEIGHT. THESE MAST SECTIONS ARE HELD ON THE LAUNCH BRACKET.

Sept. 20, 1971 BAUER EI'AL 3,605,359

ANTENNA MAST CONSTRUCTION Filed Dec, 12. 1968 2 Sheets-Sheet l INVENTORS FRANK BADER MARTIN J. BERGER ATTORNEYS Sept. 20, 1971 Filed Dec. 12. 1968 F. BADER ET MITBNNA MAST CONSTRUCTION FIG. 3

2 Sheets-Sheet 2 42 37 I v... 3O

I6 fil- |8 .t i 20 5 I l z I 62 i l I I IO INVENTORS FRANK BADER MARTIN J. BERGER ATTORNE S United States Patent Otfice 3,685,359 Patented Sept. 20, 1971 3,605,359 ANTENNA MAST CONSTRUCTION Frank Bader, Stony Brook, and Martin J. Berger, Lake Ronkonkoma, N.Y., assignors to New England Merchants National Bank, Boston, Mass.

Filed Dec. 12, 1968, Ser. No. 783,281 Int. Cl. E04h 12/08, 12/20 US. Cl. 52-146 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an antenna mast construction of the type which may be readily carried and erected by one man.

In many applications, in remote locations, it is necessary to assemble a mast upon which a transmitting or receiving antenna can be mounted. These masts may be used temporarily or, in some cases, on a semi-permanent basis. It is obvious that insofar as mobility is concerned, such masts should be highly portable and easy to assemble, yet of sturdy and reliable construction. In some situations, where it is not possible to first assemble the mast on the ground and pivot it to an upright position, it is necessary to vertically launch the mast, that is, to assemble it vertically, to its desired height which, typically, is many times the height of an individual. Prior devices designed for this purpose are generally of a complex nature and include, for example, Windlass arrangements, telescoping tube sections of increasing diameter, etc. Consequently such prior art devices were both expensive and time-consuming to launch.

The present invention provides an antenna mast of simple construction involving no moving parts, which can be used by a single individual to vertically launch an antenna mast. The mast construction, according to the invention, is lightweight and can be carried by a single man. When erected, it provides a solid foundation for an antenna or the like, and is capable of any desired degree of azimuthal adjustment without removal of the main mast guy lines. In addition, all of the mast sections are of the same construction lending to ease and economy of fabrication.

Briefly, in accordance with the invention, a mast includes a baseplate and mast section to which a launch attachment is mounted. The launch attachment includes a cylindrical housing which mates with the bottoms mast section and a launching section extending away from the housing. Additional mast sections are inserted through the bottom of the launching section and held therein by a simple slot and key locking mechanism. Successive mast sections are locked together in essentially the same way, with the addition of each such section increasing the mast height to vertically launch the mast.

The construction and operation of the invention is described in further detail below with reference to the attached drawings, wherein:

FIG. 1 is a perspective view of an erected mast according to the invention;

FIG. 2 is a top sectional view along the line 2-2 of FIG. 1;

FIG. 3 is a detailed front view, partially in section, of

a portion of the base plate and the bottom of the lowermost mast section;

FIG. 4 is a front view, shown partially broken away, showing the uppermost mast section inserted through the vertical launch attachment with a guy ring and guy lines in place;

FIG. 5 is a sectional view along the line 55 of FIG. 4;

FIG. 6 is a side view partially in section showing the slot and key mechanism by which adjacent mast sections are secured to each other; and

FIG. 7 is a perspective View of the launch attachment in accordance with the present invention.

Referring to the drawings, a mast construction according to the invention comprises a base plate 8, of any desired shape, a lowermost tubular mast section 10a extending from base plate 8, a vertical launch attachment 12 supported on the top of mast section 10a, and a number of additional tubular mast sections, here illustratively shown as three sections 1012, 10c and 10d extending from the launch attachment 12. The mast sections 10 may be made of a metal such as aluminum or a dielectric material such as fiberglass. The base plate 8 and launch attachment 12 are also of a suitable material, such as metal.

When the complete mast is erected, the mast sections 1019, 100 ad 10d are fitted together as shown. Each mast section is identical and includes an upper integral reduced diameter portion 16 (or tubular sleeve) secured to its interior surface, and protruding from the top of the mast section so as to be capable of fitting within the bottom of any of the other mast sections 10. A slot 18 (FIG. 6) is formed in the top of the reduced diameter section 16 and is adapted to retain an internal key 20 which extends diametrically across the bottom of an upper adjacent mast section 10'. An external key 22 is located on a mast section at a point, for example, about one-quarter to one-third of the section height up from the bottom in the major diameter portion. The key 22 of each section is fixed thereto and extends from the exterior surface of the mast section for retention of that section within the vertical launch attachment 12 as described below. Where any of the foregoing portions of a particular mast section 10a, 10b, 10c or 10d are described below, the letters a, b, c or d are used to identify the corresponding mast section.

The bottom of the lowermost mast section 10a is supported on a rod which is pivotally mounted on an axle 32 journalled in lugs 34 and 36 extending upwardly from base plate 8 (FIG. 3). The mast section 10a is supported on a shoulder 37 formed in rod 30. A thumb screw 42 is received in a threaded hole 43 in rod 30. Screw 42 can be threaded in to hole 43 so that the inner portion 45 of its head bears on the outer surface of the mast section 10a to fix the azimuthal position of mast section 10a to the rod 30. The base plate 8 may be secured to the ground by any suitable means such as stakes 46 which include finger clamps 48 adapted to fit into holes 50 on the base plate 8.

The vertical launch attachment 12 includes a tubular housing 52 (FIGS. 1, 2 and 4) to which a launching section 54 may be riveted as shown at 56. Alternatively, housing 52 and section 54 may be integrally formed by forging or extrusion. The housing 52 includes a locking key 57 and the bracket 54 includes a slot 58 which is adapted to receive the key 22 of the mast section 10b, 0 or d. The reduced diameter portion 16a of mast section 10a is received in the bottom of housing 52 and secured therein by retention of key 57 in slot 26. The interior of launching section 54 may be lined with a plastic bearing material to reduce friction.

Three guy lines 62 terminating in clips 64 are attached to suitable apertures (not numbered) in the launching section 54 of launch attachment 12 to stabilize the lower portion of the mast. The guy lines 62 are inserted through the eyes of stakes 66 and secured by rope clamps 68 which enable the length of guy lines 62 to be adjusted as needed. These additional guy lines 70 may be coupled to a guy ring 72 which rests on a retainer 74 (FIG. 4) to provide additional rigidity in the erected condition. The retainer 74 and the guy ring 72 are intended to be inserted on a mast section 10 at the time of its erection. The ring 72 and retainer 74 may be split so that they can be opened and conveniently installed on a mast section by inserting pins 75 of retainer 74 into suitable apertures (not numbered) in the adjacent mast section 10. As many mast sections as desired may be equipped with a guy ring and retainer. Each of the guy lines 70 has a standard releasable chip 76 attached to one of its ends. The clips are inserted in suitable apertures (not numbered) in the guy ring 72. The other ends of the guy lines 70- are inserted through the eyes of stakes 66 and retained by adjustable rope clamps 8-0 identical to clamps 68.

The mast of the present invention is erected in the following manner. After the base plate 8 is suitably secured to the ground by the stakes 46, the mast section 10a is mounted on rod 30 and pivoted to a vertical position about axle 32 and the vertical launch attachment 12 secured thereto by inserting the reduced diameter portion 16a of mast'section 10a into the larger diameter tubular housing 52. The housing 52 is locked into position by inserting its key 57 into slot 18a of mast section 10a. The guy lines 62 are then attached and the length thereof adjusted by means of the rope clamp 68 to provide a tripod which supports the mast section 10a and launch attachment 12 in a vertical position.

The next step is to insert the mast section which is to be the uppermost mast section (section 10d in the present example) through the bottom of the bracket 54. For this purpose section 10d must be turned so that the key 22d can pass within the launching section 54 as shown in FIG. 2. Mast section 10d is then pushed up until its key 22d clears launching section 54 and allowed to drop back so it is locked into section 54 by inserting its key 22d into slot 58. At this time a small portion of the section 10d extends below bracket 54. The guy retainer 74 and ring 72 may then be attached to mast section 10d. (As should be apparent, each mast section 10 must be of approximately the same size as the distance from the base plate 8 to the bottom of the mast section 10 held in bracket 54.) Clips 76 are attached to the guy ring 72 and the antenna (not shown) may be mounted on the top of the mast section 10d.

The next step is to insert the reduced diameter top 16c of the next mast section 100 into the bottom of the mast section 10d extending from the bottom of the section 54. The mast sections 10d and 10c are locked together by insertion of the key 20d of mast section 10d into slot 180 of mast section 100. The two joined mast sections are then pushed upwardly through the section 54. This removes key 22d from slot 58. Key 220 is then inserted into slot 58 to support the two sections of the mast. The third mast section 10b is added in the same way, that is, by joining it to mast section 10c and pushing upwardly and then letting the key 22b rest in slot 58. Finally, the guy lines 70 are suitably tightened by adjusting the rope clamps 80.

Once the mast has been erected, it may be adjusted in azimuth by disconnecting guy lines 62, and loosening the thumb screw 42. The mast is then rotated n rod 30 until it is pointing in the desired direction. The

thumb screw 42 is then tightened and the guy lines 62 re-attached, if desired. Since the guy ring 72 can rotate on the mast section 10d, there is no need to adjust the guy lines 70 which stabilize the upper portion of the mast and which, under normal conditions, would be out of reach of the user.

Although the invention has its principal utility with respect to the direct vertical launching of an antenna mast, the construction described and illustrated herein can also be used to erect a mast first on the ground in the manner described and thereafter raise it to a vertical position by pivoting it about the axle 32.

Thus, the invention provides a relatively inexpensive mast construction which can be used with ease to raise a mast vertically without any complex mechanical mechanisms. Moreover, the construction of the invention has advantages with respect to portability and manufactur' ing in that it may be stored in a package no longer than the length of the individual mast sections and all of its parts may be fabricated with relative ease.

Various modifications of the invention will be obvious to those skilled in the art and the invention therefore, should be defined with reference to the attached claims.

What is claimed:

1. A mast construction comprising a base, a first mast section mounted on the base and a launch attachment secured to the upper end of said section, said launch attachment comprising a first portion secured to the said section and a second portion laterally of said first portion defining a through opening in parallel offset relation to said first mast section, a slot in said second portion, a second mast section comprising an elongated tube mounted in said second portion, key means on said tube inserted in the slot for supporting the tube in said second portion, and a series of tube joined end to end mounted on the second mast section, each tube being of the same external diameter as the second mast section and of a length less than the distance between the base and second portion whereby the tubes can be assembled by insertion through said through opening.

2. A mast construction as defined in claim 1 wherein the tubes are joined by means comprising a reduced diameter segment of one tube inserted in the adjacent tube and a key mounted within the said adjacent tube extending into a slotted portion in the said one tube.

3. A mast construction as defined in claim 2 further including a key means on each tube of a size to be insertable in said slot in said second section.

4. A mast construction as defined in claim 2 further including means in said launching section for connection with guy lines whereby to stabilize the lower portion of the mast and means secured to at least one of the tubes of the series for connection with guy lines to stabilize the upper portion of the mast.

References Cited UNITED STATES PATENTS 253,743 2/1882 Mensing 52-123 2,356,085 8/ 1944 Plaff 521 17 2,992,710 7/1961 Thomson 52-123 3,004,635 10/1961 Langmack 521 16 3,110,368 11/1963 Ross 52--121 FOREIGN PATENTS 350,596 1931 Great Britain 52-121 473,847 1914 France 52-l21 HENRY C. SUTHERLAND, Primary Examiner US. Cl. X.R. 52116, 726 

